I have just visited windows update and gone through the validation thingy for the first time.
This is what it says:
"The scan of your computer has completed. The Windows product key associated with your copy of Windows maps to one of the major PC manufacturers who purchase Windows product keys from Microsoft. The specific product key found on your computer maps to a major PC manufacturer that sells different hardware than the hardware found on your machine. This will not prevent you from validating now, but may cause you problems in the future. Please click Continue to complete the validation process."
What on earth! The only new hardware I have since buying the laptop is a PCMCIA wireless networking card.
This is 100% legit. The manufacturer is a well known one as is the high street chain from which I purchase the Laptop.
You validation process would have completed successfully, despite the worrying wording. Even if you'd changed major components and a phone call to MS is required to re-validate your licence, I've heard that this is a cursory process. So I don't think you need expect any problems in the future.
"maps to a major PC manufacturer that sells different hardware than the hardware found on your machine"
means - MS don't yet know that this mfr sells this hardware (or haven't been told by the mfr). I'm not amazed at such lack of co-ordination - but since you clearly have not done anything wrong, there is no cause for concern.
Microsoft are just pointing out to you that something is different on your system to what was expected.Don't take it personally it's quite possible that because you bought secondhand something was replaced prior to you buying it. Chill out and have a cup of tea